How to iterate through XML in Powershell?

Question

I have this XML document in a text file:

<?xml version="1.0"?> <Objects>   <Object Type="System.Management.Automation.PSCustomObject">     <Property Name="DisplayName" Type="System.String">SQL Server (MSSQLSERVER)</Property>     <Property Name="ServiceState" Type="Microsoft.SqlServer.Management.Smo.Wmi.ServiceState">Running</Property>   </Object>   <Object Type="System.Management.Automation.PSCustomObject">     <Property Name="DisplayName" Type="System.String">SQL Server Agent (MSSQLSERVER)</Property>     <Property Name="ServiceState" Type="Microsoft.SqlServer.Management.Smo.Wmi.ServiceState">Stopped</Property>   </Object> </Objects> 

I want to iterate through each object and find the DisplayName and ServiceState. How would I do that? I've tried all kinds of combinations and am struggling to work it out.

I'm doing this to get the XML into a variable:

[xml]$priorServiceStates = Get-Content $serviceStatePath;

where $serviceStatePath is the xml file name shown above. I then thought I could do something like:

foreach ($obj in $priorServiceStates.Objects.Object) {     if($obj.ServiceState -eq "Running")     {         $obj.DisplayName;     } } 

And in this example I would want a string outputted with SQL Server (MSSQLSERVER)

Answer 1

PowerShell has built-in XML and XPath functions. You can use the Select-Xml cmdlet with an XPath query to select nodes from XML object and then .Node.'#text' to access node value.

[xml]$xml = Get-Content $serviceStatePath $nodes = Select-Xml "//Object[Property/@Name='ServiceState' and Property='Running']/Property[@Name='DisplayName']" $xml $nodes | ForEach-Object {$_.Node.'#text'} 

Or shorter

[xml]$xml = Get-Content $serviceStatePath Select-Xml "//Object[Property/@Name='ServiceState' and Property='Running']/Property[@Name='DisplayName']" $xml |   % {$_.Node.'#text'} 

Answer 2

You can also do it without the [xml] cast. (Although xpath is a world unto itself. https://www.w3schools.com/xml/xml_xpath.asp)

$xml = (select-xml -xpath / -path stack.xml).node $xml.objects.object.property 

Or just this, xpath is case sensitive. Both have the same output:

$xml = (select-xml -xpath /Objects/Object/Property -path stack.xml).node $xml   Name         Type                                                #text ----         ----                                                ----- DisplayName  System.String                                       SQL Server (MSSQLSERVER) ServiceState Microsoft.SqlServer.Management.Smo.Wmi.ServiceState Running DisplayName  System.String                                       SQL Server Agent (MSSQLSERVER) ServiceState Microsoft.SqlServer.Management.Smo.Wmi.ServiceState Stopped